Peptic ulcer, such as gastric ulcer and duodenal ulcer, is considered to have developed as a result of self-digestion caused by imbalance between aggressive factors, such as acid and pepsin, and protective factors, such as mucus and blood.
The treatment of peptic ulcer is carried out by internal medicine in principle, and various drug treatments have been attempted. Particularly, drugs specifically inhibiting H+-, K+-ATPase, an enzyme present in gastric parietal cells and in charge of the final step of gastric acid secretion, suppressing the acid secretion and thereby preventing self-digestion, for example, omeprazole, esomeprazole, pantoprazole, lansoprazole, rabeprazole, etc., have been recently developed and clinically used.
Although these drugs have excellent therapeutic effects, drugs which have more long-lasting inhibitory effect on gastric acid secretion, higher safety and more suitable physicochemical stability are further required.
Compounds especially relevant to the present invention are described in the patent documents 1 to 3 but the specific compounds described in these patent documents and the specific compounds of the present invention are different in the chemical structure.
Patent Document 1 JP-A-62-207271
Patent Document 2 EP-A-0254588
Patent Document 3 EP-A-0187977